FIG. 6.

Upregulation of MHV-68 gene expression by PGE₂. (A) BHK-21 cells were untreated (left panel) or pretreated with 1 μM PGE₂ (right panel) before infection with wt MHV-68. Cells were maintained in medium containing 1 μM PGE₂ during the infection and postinfection incubation (right panel). Total RNA was harvested 8 h postinfection, and labeled cDNA probe was generated for hybridization to MHV-68 DNA arrays. The ORFs are printed below each array element. (B) A STORM phosphorimager and ImageQuant system were used to quantitate the signal from the array elements corresponding to 73 known and predicted MHV-68 ORFs. GAPDH-normalized values from the array with PGE₂ (A, right panel) were divided by the corresponding GAPDH-normalized values from the untreated array (A, left panel) to derive the fold induction of gene expression relative to the untreated level for each array element. These values and their corresponding MHV-68 ORFs are ordered in the bar graph based on increasing fold induction of gene expression relative to the untreated level. Statistical significance of differences in expression was assessed by paired t test.